Ore-roasting furnace



(No Model.) 5 Sheets-Sheet 1.

' S. B. DEXTER.

ORBQROASTING FURNACE.

No. 436,340. l Patented Sept. 16, 1890.

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(No Model.) 5 Sheets'Sheet 2. 7

- S. B. DEXTER.

'ORE ROASTING FURNACE. No. 436,340. Patented Sept. 16, 1890'.

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ATTORNEYS.

(No Model.) 5 Sheets-Sheet 3.

S. B. DEXTER. ORB ROASTING FURNACE. No. 436,340. Patented Sept. 16,1890.

WITNESSES: M/l/E/VTOR ATTORNEYS.

(No Model.) 5 Sheets-Sheet 4.

S. B. DEXTER.

ORE ROASTING FURNACE.

By M AIME/V578.

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(No Model.) 5 Sheets-Sheet 5.

S. BJD EXTER.

ORE ROASTING FURNACE.

No. 436,340. Patented Sept. 16, 1890.

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UNITED STATES PATENT OFFICE.

' SIMON n. DEXTER, OF GLENDALE, MONTANA.

ORE-ROASTING FURNACE.

SPECIFICATION forming part ofLetters Patent No. 436,340, dated September16, 1890.

Application filed October 6, 1888.

To all whom it may concern.-

Be it known that I, SIMON B. DEXTER, of Glendale, in the county ofBeaver Head and Territory of Montana, have invented a new and ImprovedOre- Roasting Furnace, of which the following is a specification,reference being had to the annexed drawings, forming a part thereof, inwhich-- Figure 1 is a side elevation, partly in section, of the furnaceand collecting-chamber. Fig. 2 is a vertical transverse section of thefurnace, taken on line as no in Fig. 3. Fig. 3 is a horizontal sectiontaken on line y y in Fig. 2. Fig. 4 is a horizontal section taken online ,2 z in Fig. 5. Fig. 5 is a vertical transverse section taken online z z in Fig. 3. Fig. 6 is an enlarged sectional end elevation of thereceiving-car. Fig. 7 is a plan view of the bottom plate of the furnace;and Fig.8 is an enlarged detail side elevation of the orefeeding pipes,showing the dust-receiver in section.

Similarletters of reference indicate corresponding parts in all theviews.

- The object of my invention is to construct an ore-roastin g furnace inwhich the ore-dust may be treated by passing it through the furnace inthe direction of the draft of the fires of the furnace, thereby insuringa thorough treatment of the ore Without appreciable waste of material.

My invention consists in the construction and arrangement of partshereinafter described and claimed.

The furnace A is provided with a central vertical chamber a, whichis'surrounded by a double wall B, in which are formed the fines b b b bc c c a which will be hereinafter more fully described. Outside of thefines is formed an air-space d,which extends entirely around the body ofthe furnace and reaches from a point near the bottom of the furnace to apoint near the top thereof.

In the side walls of the furnace are inserted pipes e f, whichcommunicate with the space d and serve to supply air to the said space,the air taking up heat in its passage through the space, therebyeffecting two important results-via, the heating of the air supplied tothe fire-chambers O O at opposite ends of the furnace and reducing theescape of heat through the outer portion of the wall. The fire-chambersO O are built in the Serial No. 287,374. (No model.)

wall of the furnace and open into the chamber ca near its lower end. Ineach fire-chamber is placed a water-grate D, formed of tubes andreturn-bends and communicating with the water supply and discharge pipesg h. Below the water-grate D thereis an ash-pit c, and above and belowthe grate, upon opposite sides thereof, are air-blast apertures j k,which communicate with the air-space d. The water entering thewater-grate D through the pipe 9 is discharged after its passage throughthe grate into the ash-pit i, whence it flows, together with the ashes,through the discharge-pipe h.

The fines b b at one end of the furnace and b b at the opposite end ofthe furnace are bowed outward away from each other to allow them to passaround the firechambers O and C, the lower ends of the fluescommunicating with the chamber a below the fiI'G-Ghftl11 bers, and theupper ends being arranged to discharge into the dust-receiving chamber Eat the top of the furnace. The fines c c 0 0 communicate with thechamber a at a point below the fire-chambers, and also extend upward tothe dust-receivin g chamber E. Below the fire-chambers and below theopenings in the flues b b b b are formed passages Z for the insertion ofbars or tools for working the mass melted in the furnace.

In the lower part of the furnace-wall is arranged an apertured dividedplate F, which rests upon the foundation of the furnace and serves as anabutment for the receptacle G, carried by the car II. The plate F is provided with a water-passage m, which extends entirely around the plateupon its upper surface, the halves of the water-passages being connectedby return-bends n. The plateF is made in halves for convenience inremoving it from the furnace when injured by heat. 'Water is allowed toflow continuously through the passage on to prevent the rapiddeterioration of the plate. To remove the plate F, a portion of themasonry is first removed, and after repairs have been made and the plateagain inserted the masonry is rebuilt.

The car H is supported by a platform I, which rests upon rods 0,pivotally connected with the platform, and received upon cranks p,carriedTby gear-Wheels q, mounted on shafts r. The platform I andgearing connected therewith are placed in a pit J, formed under I thefurnace, and the shafts a" are made to rtate together, but in oppositedirections, by the engagement of the two pairs of gearwheels q. One ofthe shafts a" is provided with a sprocket-wheel s, which receives achain t, driven by a small sprocket-wheel 10, mounted on a shaft 1),which receives motion from any convenient power. An iron casing G,surrounding the receptacle G, is supported by springs G attached to thebody of the car, so that when the car is pushed upward the casing G willbe first brought into contact with the plate F, after which thereceptacle G may be carried upward until it strikes the said plate F. Inthe brick-work supporting the plate]? .is arranged a water-pipe F,having sprinkler-openings on the side facing the casing G. The said pipeis supplied with water through the feed-pipe F The sprinkler is designedto prevent the adhesion of fused ore to the inner surface of the casingG and the receptacle G.

The platform I is provided with a standard (1', which is engaged by thecatch-lever c 6 carried by the car H. Thecar moves in the directionindicated by the arrows in Fig. 2, and when the standard d is reached bythe catch-lever e the said catch-lever drops behind the standard d,while the catch-lever 6 serves as a stop for arresting the motion of thecar. When it is desired to remove the car from the furnace thecatch-lever e is lifted, when the car may be moved on.

The chamber a is surrounded at its upper end with a water-jacketed framef, in which is hinged a hollow cover 9, the said cover being providedwith ahollow shaft 71., by which it may be opened or closed. The hollowshaft 72/ is journaled in standards 2', resting on the top of the bodyof the furnace. Water is introduced into the hollow shaft it through thepipej and is discharged through the pipe the shaft h being provided atopposite ends with stuffing-boxes Z. The hollow coverg is provided witha central partition 0%, which extends from the hollow shaft h to a'pointnear the free end of the cover, the hollow shaft being stopped also at acorresponding point and provided with apertures on opposite sides of thepartition. By this arrangement the water is made to flow through thehollow shaft into one .side of the cover g and around the partition m,thence outwardly through the hollow shaft. The cover 9 iscounterbalanced by weighted levers n" attached to the shaft nearopposite ends. To one of the levers n is pivoted a rod 0 for turning theshaft h and operating the cover g. By thus having a cold surface closingthe upper end of the chamber a the rising heatcurrent contactingtherewith is suddenly cooled and precipitated downwardly, therebyassisting the downward draft of the furnace as wellas protecting thedamper from injury.

At the top of the chamber E is avertical pipe J, provided at its lowerend with an inclined dust-carrying pipe 19 and furnished at its top witha cover q, pivoted to one end of the lever r, the opposite end of thesaid lever being provided with the rod 3, by which the cover may beraised or lowered.

Adjoining the furnace A is a chamber K, having an inclined bottom andfurnished with a discharge-pipe 11/, located at the front of thechamber. In the said chamber K are deposited the finely-powdered ores ordust from the mill, and at the side of the chamber K is arranged acollector L for receiving the dust and fine particles of ore dischargedfrom the dust-chamberE through the pipe 19 which communicates with thesaid collector L at a point near its middle. The collector L is providedwith a smoke-pipe M, having a damper t and is also furnished with adischargepipe to, which empties into a receiver M, the saiddischarge-pipe being provided with a valve 6 by which the flow of dustto the receiver a may be regulated or stopped altogether. Thedischarge-pipe u, is provided at its lower end with a nozzle extendinginto the receiver a and furnished with a valve (P.

In the side of the discharge-pipe u, are arranged gate-valves f f f fwhich permit of taking the dust from any level of the chamber K. Anordinary endless-belt elevator N takes the dust from the receiver acarries it to a point above the top of the furnace A, and discharges itinto a chute O, which terminates in a pipe 9 which reaches into thecenter of the chamber a. In the upper portion of the chute O is insertedan air-blast nozzle 7L2, which communicates by the pipe 1? with theblower P, the air from the said nozzle being employed to drive the dustthrough the chute O and pipe g into the chamber a. It will be understoodthat the force of this blast is not to drive the dust through thefurnace, but is just sufficient to overcome the force of the rising heatand permit the dust to fall by gravity only through the roasting orfusing chamber. If a blast were used, it would cause much of theore-dust to pass through the draft-flues unacted upon; but as I only usea natural draft and the dust falls from the top of v the chamber throughall of the heated space and nears the intensest heat as it falls itfollows that'it will be thoroughly roasted or fused, as the case may be.The blast in the feed-pipe is also to prevent the draft from passingthrough the feed pipe when the damper 'is opened to reverse the draftwhen a car is to be removed.

Then the furnace is in operation, the ore discharged through the pipe ginto the chamber a is heated to the required degree in the said chamberand drops into the receptacle G of the car H, the movement of the orebeing in the same direction as the draft of the furnace. Any very fineparticles which do not find their way to the receptacle G are carried upthe fiues b b b Z2 0 c c c and delivered by the pipe 1) to the collectorL. When asufficient quantity of roasted ore has been collected in thereceptacle G, the car H is low- ICS ered after stopping oh: the supplyof ore by closing the valves 61 e and opening the covers g g. The filledcar is replaced by an empty one, and the process is carried forward asbefore. Should any of the roasted ore or fused metal adhere to the sideof the chamber a it may be loosened by inserting proper implements inthe passages Z. The height of the furnace may be extended with advantageto a point Where the heat of r the fire is ineffectual in melting theore.

Having thus described my invention,l claim as new and desire to secureby Letters Patent- 1. An ore-roasting furnace comprising the verticalroasting-chamber having an outleton top for the waste gases and productsof combustion, side fire-chambers near its lower end, verticalupdraft-fines through its walls from below the fire-chambers anddischarging into said outlet, an outlet for the treated ore at thebottom of the roastingchamber, a dustfeeder at the upper end below thesaid outlet for the waste gases, and a blast-pipe dischargforce of theascending heat, substantially as set forth.

2. An ore-roasting furnace comprising the vertical roasting-chamberhaving side firechambers in its lower end, a damper at its upper end,draft-fines leading from its lower end below the fire-chambers, anoredust feeder discharging into the upper end of the roasting-chamberbelow its damper, and an outlet for the fused or agglomerated ore at thebottom of the roasting-chamber, whereby when the ore is being removedfrom the bottom of the chamber the damper may be opened to reverse thedraft, substantially as set forth.

3. A11 ore-roasting furnace comprising the vertical roasting-chamberhaving side firechambers in its lower end, a chamber above theroasting-chamber provided with an upper and a lower damper, a pipeleading from the space between said two dampers, a dust-col lector intowhich said pipe discharges, a chimney leading from said collector andprovided with a damper, and fines leading from the roasting-chamberbelow the fire-chambers upwardly into the chamber between the twodampers, substantially as set forth.

4:. An ore-roasting furnace comprising a vertical double-Walled chamberat, having an outlet at its lower end, a space (:1 being formed betweenthe two walls and provided with airinlets,the side fire-chambers O O atthe lower end of the chamber ct, horizontal grates within said chambers,air-blast apertures j above and below the grates at opposite sidesthereof communicating with the space d,draftfiues leading from thechamber at below the fire-chambers, and an ore-feeder discharging intothe upper end of the chamber a, substan' tially as set forth.

5. The combination,withtheroasting-chamher having side fire-chambers inits lower end, draft-fines leading from the chamber be low thefire-chambers, and an ore-dust feeder discharging into the upper end ofthe roasting-chamber, of a dust-receiving chamber on top of the furnaceand into which said draftflues discharge, a dust-collector, a pipeleading from the dust-receiver thereto, an outlet for the saidcollector, and a conveyer for returning the dust to the upper end of theroastingchamber, substantially as set forth.

6. Thecombination,withtheroastin -chamher having a dust-feeding pipedischarging into its upper end, side fire-chambers in its lower end,draft-fines leading from the roasting-chamber below the fire-chamber,and a dust-receiver on top of the furnace into which said finesdischarge, of a dust-collector, a pipe connecting it wit-h the receiver,areceptacle into which the collector discharges, an ore-dust chamberalso having an outlet discharging into said receptacle, and mechanismfor conveying the dust from the said receptacle to the dust-feeding pipeof the roasting chamber, substantially as set forth.

7. The combination, in a downdraft oreroasting furnace, with thevertical roastingchamber having an open upper end, side firechambers,draft-fines below said chambers, and an ore-feeder discharging into thechamber above the fire-chambers, of a cooled damper at the upper openend of the chamber, and provided with aninlet and outlet for the coolingmedium, whereby the ascending hot gases will be chilled and assist thedown ward draft of the furnace, substantially as set forth.

8. An oreroasting furnace consisting in the roasting-chamber having sidefire-chambers in its lower end, draft-flnes leading from theroasting-chamber below the fire-chambers to the top of-the furnace, aremovable receptacle in the bottom of the roastingchamber, a

damper at the upper end of the said chamber, a receiver on top of thefurnace, into which said draft-fines and damper open, a pipe J extendingfrom said receiver and provided with a cover, a dust-collector having achimney leading from its upper end and a dustoutlet at its lower end, apipe leading from the receiver to the collector, an ore-dust feederentering the upper end of the roasting-cha1nher, and a conveyersupplying said feeder with ore-dust and furnace-dust from the collector,substantially as set forth.

9. The combination, with the roasting-chamber and its feeder, of anelevator discharging into the feeder, and an ore-receptacle K, hav- ICCing a vertical pipe u, delivering to the elevator, and having a seriesof gatevalves at different heights, substantially as set forth.

S. B. DEXTER. Witnesses:

Gno. M. HOPKINS, G. SEDGWIOK.

